Short wave signaling



N. E, LlNDENBLAD SHORT wAvE SIGNALING Nov, 29, 1938.

' r Original Filed lJam. 14, 1933 2 SheetslSheet 2 INVENTOR NILS E.,L| ENBLAD y ATTORNEY' cuits and also as means for. conducting cooling Patented Nov. `29,

UNITED STATI-:s

snoa'r WAVE slaisanrizo.l

' Nils E. Lindenblad, Port Jefferson, N. Y., miglior to Radio Corporation oiLAmei-lca, a corporation Delaware original application .ianuuy 14, 1933, semi No.

651,839.` Divided and this application Decembaz3, 1933. sei-1n No. 703,850

27 Claims.

My present invention, which is a division of my copending application Serial Number 651,809, led January 14, 1933, now United 'States Patent No. 2,052,888, granted September 1, 1936, has for one of its objects, the provision of means for the production of Fshort waves at very high power. A further object of my present invention is to provide a fluidA or water cooled amplifier and/or oscillator` system especially adapted for the high powered amplification of very short waves.

An important feature of my water cooled system is the provision of -clrcuits which serve the dual function of acting as high frequency cirfluid to and away from the tubes forming the amplier and/or water cooled'oscillatlon generator. My water cooled amplier and/or oscillation generator is further characterizedby the fact that the circuits are arranged in such a way that no radio frequency insulators `are required and in this manner increases the eiliciency of the short wave system to say nothing of the presentation of many mechanical advantages. p f

As a further feature I have provided an interlocking system for the water cooled amplifier and/or oscillator which serves to shut down the oscillator electrically should the lament current. plate voltage, or water supply `ifail.

Still other objects, as well as advantages andl features of my present invention, willbecome apparent as the more detailed description thereof proceeds. 'Ihis detailed description may best be understood by referring to the accompanying drawings wherein the same parts are represented by the same reference numerals.

'In the drawings:

Figure 1 illustratesmy improved fluid cooled system andan vinterlocking arrangement thereor,

Figure 2 illustratesin greater detail the mechanical construction of my water cooled high frequency amplifier of Figure 1 and also shows vhow that amplifier maybe used as an oscillation.

generator in a short wave transmission system; and, j

Figure 3 shows in detail the mechanical con struction of the filament heating circuit used for the water cooled ampliiier of Figures 1 and 2.

'Referring to -Figure 1, a suitable source of energy (not shown) feeds, through transmission line 286, the tunable output or grid circuit 294 of the fluid or water cooled tubes 296, 299. The input circuit 294 ,as-shown, is formed of two conductors having uniformly distributed inductance and capacity tuned by adjustment of slider 295 (Gl. Z50-27) in contact with the input conductors 299, 300

forming the input circuit. Gri'd or control electrodebias for the grids of tubes 296, 293 is ob.- tained due to rectification action by the use of resistor 302 connected to the conductor slider 295, The filaments of the tubes 296. 29B are en-y ergized from the A. C. supply line 304, filament temperature control being obtained by means of variable resistor309.

The filament or cathode circuit of the tub'es 298, 298 consists of the conductor tubes 300, 310 connected through short circuiting strap SI2 to one terminal of the secondary winding of iilament transformer 3I4. The low frequency A. C. heating energy, therefore, passes from the righthand terminal of the secondary winding of transformer 3|4 over theouter surfaces of tubes 309, 310, through the righthand lament leads and is returned through the inner conductors within the tubes308, 3l0 to the other terminal of the secondary winding of transformer 3I4 through connection 320. The impedance of the lament 'circuit is adjusted by means of Suder an, and

the mament heating conductors for each tube are arranged to act in parallel for the .high fre-l quency currents by virtue of by-passing condensers 324.

The electrodes of the tubes 299, 293 are enclosed by the iiuid cooling or water cooling cham.

able fraction of the operating wave length. The

Ihollow conductors 334, 330 are electrically and fluid flow connected together by means of a header or T-shaped'element 333 to which the voltage supply lead 332 is connected. 'I'he high voltage supply, consequently, is fed to a point of minimum radio frequency potential, or, putting it another way, to the electrical center of the U`- shaped water cooled anode conductor structure comprising thelinear tubes 334, 330. The linear tube structure, forming part of the `high frequency circuits are of appreciable length relative tothe operating wave length so that there isan appreciable fall in potential across portions there-.- of at the operating frequency.

In similar fashion, tubes 340 and 342 also linear or`substantially straight, hollow, and made of conductive material such as copper, are 'electricallyand uid flow connected to the iiuid cooling chambers 320, 323. 'I'he tubes 340, 342 are also connected together to form a U-shaped con# 55' ductive loop by the header` or T-shaped element l344, in turn supplied with cooling fluid, auch as water, through the coiled rubber pipe 346 which j the pipes or tubes 340, 342, through the fluid cooling chambers 326, 323 electrically as well as y flow associated with the anodes of the tubes 296,

296. From the fluid cooling-chambers, the fluid cooling water flows through the tubes 334, 336 through header 333 and through rubber hose 350 coiled about form 362, out through valve 354. This coolingwater flowing out from .valve 364 may then be suitably cooled bymeans of a condenser Q(not shown) and repumped, if desired, through tube 346 by a suitable pump not shown. If desired the ilow of water may be reversed; The impedance or tuning of each of the U-shaped cooling circuits for the anodes of the water cooled amplier tubes 296, 293, is separately adjusted by means of the conductive sliders 356, 353.

By suitable adjustment of the sliders and potentials applied to the water cooled amplifier, it can be made to act either as an oscillation generator in which case it may be locked into step y with the oscillations supplied through high frequency transmission line 236, or it can be made to act as a suitable amplier supplyingoscillations in its output circuit formed of conductors 334, 336, only when input potentials are applied to the input circuit 294.

The mechanical construction of my fluid cooled short wave system may be more clearly observed by referring to Figures 2 and 3, in the former of which it is illustrated as a self oscillation generator. Thus, referring to Figure 2, the tubes 236, 293 are connected to the water cooling chambers 326, 323. Cooling water is supplied through the rubber hose water inlet pipe 346jwrapped about form 346. This cooling water is then fed to the T-shaped header 344 from .whence the water di -vides and ows up tubes 340, 342 into the bottom .of the cooling chambers 326, 323.. The cooling water and iluid then flows through the pipes or tubes 334, 336 where it is joined in the T-shaped header 338 and removed by way of rubber hose 356 wrapped about the common form 343.

The grid circuit 294, as shown in Figure 2, consists of the two tubes or conductors 293, 303. The slider 295, of course, may be moved along the length ofthe conductors 299, 300 for tuning purposes, and' grid biasing potential is supplied through conductor 360 connected to the brass gterminal 362, in turn connected to the grid condiagrammatically in. Figure 3, .the secondary of transformer 3l4 is connected to the iilament supply terminals 366, 363. Heating current may then ow from terminal 366 and the brass conducting piece 310 down the lament tubular conductors 393, 3I0 into the `filamentsl by way of the metal straps 312 and filament terrien-rais 314. The return current fromv the filaments passes through the terminals 316, the conductors within the tubes 303, 3l3 through conductive connection 313 to the other filament supply terminal 363. 'I'he condensers 324 shown in Figure l may be formed by the capacity existing between the copper straps or nmetallic connectors 330 and 332 which, of course. areseparated by some suitable insulation such as the mica bushings 334. The filament tuning strap 322, as shown in Figure 2, is, for longer waves, placed as closely to the tubes as possible forming a fairly direct short circuit between the filaments or cathodes. When shorter waves are to be cproduced, this slider islocated further away but not necessarily a half wave length away from the filaments, although successful operation will be obtained even at that adjustment.

Either of the tubular plate circuits arranged at right angles to one another may be used as an output circuit. One pair may, if desired, be adjusted as a high impedance vsupports and all of. the tuning accomplished by adjustment of the slider on the other pair of tubular conductors, or, both circuits may be tuned and worked in parallel. Also, if desired, it is not necessary that the water tube circuits be arranged at right angles, but, a single pair of tubes or pipes may be used, e'ach tube of the set being longitudinally divided into two compartments so that the same tube provides for inlet and outlet fluid ow. Also, if desired, although not preferable, the plate water cooling circuits may be arranged at lan angle other than at right angles either obtuse or lacute, and if desired may be arranged to run parallel to each other.

As shown in. Figure 2, the 'output energy is fed through transmission line 390 to a half waveradiator 332 provided with a parabolic re'ector 334 for unidirectional propagation.

The T-shaped headers on the anode tubes and the brass terminal piece 362 on the grid tubes, as well as the connections such as 3|2 (see Figure 1) for the filament tubes are voltage nodal points for the high frequency currents and this construction oifers decided mechanical and electrical advantages. That is, these points, need only be insulated for the D. C. potentials, and may be held at ground for the radio frequency potentials besides serving as points for mechanically supporting the entire arrangement. Thus, as shown in Figure 2, the tubes are ilrmly supported at point 362, at the water headers 344.and 333 and by the filament supply circuit by attachment to the wooden framework, or, if desired, suitablyinsulated metallic supports. s As shown in Figure 2, in addition to The various sliders may.. be used for adjusting the various circuits to various impedances or desired tunings. Output energy is taken froml a point away from the plate sliding tuner on the horizontal conductors 334, 336 shown in Figure 2 at points such that the impedance of the hollow conductors between the tapping points and the slider equals the surge impedance of the transmission line 390, or as shown in Figure l, equal to the surge impedance of the transmission line 390 which may feed the ilnal frequency multiplier and amplifier. i

To repeat, because oi the unique construction of the water cooled amplifier. no radio frequency insulators are required, and this, as already indicated, is an important advantage inasmuch as'one of the most troublesome features in the high frequency field is the problem of providing suitable radio frequency insulation.

amarsi f M There has also been provided, as shown in Figure 1, an interlock system to prevent the destruction of the tubes in the water cJooled amplifier stage due to failure of either cooling fluid or electrical-energy. In the event of water failure. the valve armature of valve 354 will drop, opening contacts 306. The opening of contacts 390 will consequently break the circuit from the bus |04 through electromagnet 398. Simultaneously, electromagnets 400 will become deeny ergized as a result of which the primary of transformer 3|4 will be opened causing 'the deenergization of the filaments of thewater cooled ampliiler.. At the same time deenergization of the electromagnet 400 will open .circuit 402 causing deenergization of the high voltage rectifier 330 thereby removing plate potential from the water cooled amplifier. Upon a return of cooling water supply the system must be manually reinstated 'by means of push button 404.

Assuming the alternating current source 304 for the high voltage rectifier 330 and for the filaments of the water cooled amplifier to fail, then, electromagnet 40B will become deenergized and successively electromagnets 398 and 400 will become deenergized causing the action as describedabove. I-Iere again, return of the source of alternatingcurrent at 304 will not cause the system to start up, but manual reinstatement must be made by means of push button 404. It should be obvious, of course, why this interlock is provided, for failure of water supply would cause the rapid deterioration of the expensive water cooled tubes 296, 298; and, if the filaments were energized with the high plate potentialon, they would be subjected to high undesirable stresses in their relatively cold condition.

The input to the high frequency water cooled amplifier from transmission line 286, is fed to the conductors of the input circuit 294 at points so spaced away from the short circuiting strap 295 that the portions of the conductors included between the tapping points and the short circuit-A ing strap have an impedance substantially equal in value to the surge impedance of transmission line 286 to prevent dissipation of power.

'I'he transmission line 390 need not be tapped on to the 'conductors 336, 334 through blocking condensers 4I0, but may be-spaced from short circuiting or tuning strap 358 so as to suitably load the power amplifier.

Many minor changes may, of course, be made in the arrangementsl which I have described. Accordingly, my present invention is not to be limited by the exact illustrations or specific descriptions given herewith but is to be given the full scope and breadth indicated in the appended claims. J

4 ,Having thus described my invention, what I claim is:

. l. -An ultra high frequency system comprising an electron discharge device having a i'luid cooled chamber, a linear conductor electrically and flow connected to said chamber for supplying cooling iluid thereto, another linear conductor electrically and flow connected to said cooling chamber for removing cooling uid therefrom, one of said conductors forming a portion of`a high frequency circuit and being va substantial fraction of the operating w'ave length long, and means for varying the eifective electrical'length of one of said conductors. 1

2. A iluid'cooled ultra high frequency system comprising 'a hollow. linear conductor of appreof the system, means for causing cooling fluid to pass therethroughl means for causing currents of the desired operating wave length to flow -tem electrically and ilow connected to said chambers, the linear portion of said conduit system being of appreciable length relative to the operating wave length, means for causing cooling uid to pass through said conduit system, means for causing high frequency currents to flow over said conduit system, and means for varying the effective electrical length of said conduit system.

4. A cooled ultra high frequency system comprising a circuit consisting of a pair of hollow linear conductors having appreciablelength relative to the operating wave length, means for causing 'cooling fluid to pass through said linear conductors, means for causing the ow of high frequency currents in said conductors. andmeans for varying the' effective electrical lengths of said hollow conductors.

5. A cooled ultra high frequency system comprising a pair of electron discharge devices each having a fluid cooled chambena pair of hollow linear conductors electrically and flow connected to said chambers, means for causing cooling fluid to pass through said conductors and said chambers, means for causing high frequency currents to flow in said conductors whereby'throughout a portion 'of the length of said conductors there shaped conductors lbeing each at least as long as an appreciable fraction of the operating wave.

7. A cooled ultra high frequencysystem com- Y prising a pair of-electron discharge devices each havin'g a uid cooled chamber, a hollow U-shaped conductor system connected to said chambers, -another hollow U-shaped conductor system also connected to said chambers, and means for causing the flow of cooling fluid through said U-shaped conductors and chambers, .and a. strap connected across the legs of one of saidiU-shaped conductors for adjusting the impedance thereof, said last U-sliaped conductor having a length at least equal to an appreciable fraction-of the operat- 1 ing wave..

8. A cooled ultra high frequency system comprising a pair of electron discharge devices each having a fluid copied chamber, a hollow U-shaped conductor'system connected to said chambers, another hollow U-shaped conductor system also connected to. said chambers, means for causing the iiowof cooling. iiuid through said' U-shaped conductors and chambers, and a strap connected across the legs of each of said U-shaped hollow conductor systems for tuning same,- said U-shaped conductors having a length at least equal to an appreciable fraction of the operating wave.

9. A cooled high frequency system comprising a pair of electron discharge devices, each having a fluid cooled chamber, a hollow ALi-Shaped conductor system connected to said chambers, another hollow U-shaped conductor system at an angle to said ilrst U-shaped conductor system also l connectedto said chambers, and 'means for causing the flow of cooling uid through said U-shaped conductors and chambers.

10. A cooled high frequency system comprising a pair of electron discharge devices each having a uid cooled chamber, a hollow U-shaped conductor system connected to saidchambers, and another hollow U-shaped conductor system at right angles to said first hollow U-shaped conductor system also connected to said chambers, and means for causing the flow of cooling uid through/said U-shaped conductors and chambers. J

11. High frequency apparatus comprising a pair of "tubes each having an anode, a grid, and a cathode, a U-shaped' conductor connected between said cathodes, a U-shaped conductor connected between said grids, and a U-shaped conductor connected between said anodes, the conductors connected between' said anodes and cathodes being arranged in a vertical plane and the conductors connected betweensaid grids being, arranged in a horizontal plane.

l2. Apparatus as claimed in claim 11 -characterized by the fact that means are provided for mechanically supporting said tubes and circuits at the conductor portions connecting together the legs of one or more of said U-shaped conductors.

13. A cooled ultra high frequency system comprising a pair of electron discharge devices each having a uid cooled chamber, a U-shaped hollow conductor system electrically and ow connected to said chambers, means for causing cooling iluid to pass through said hollow conductor and said chambers, and means for varying the effective electrical length oi! said U-shaped conductor system, said U-shaped conductor having a length equal to at least an appreciable fraction oi' the operating wave.

14. High frequency apparatus comprising a pair of tubes each havingan anode, arcathode, and a grid, a U-shaped conductor connected between said anodes, a U-shaped conductor connected between said grids, anda U-shaped conductor connected between said cathodes, said U- shaped conductor connected between said grids on said conductor.

being arranged in a plane perpendicular to the plane or planes in which said other U-shaped v conductors lie, and an additional U-shaped conductor connected between said anodes, said ad` ditional U-shaped conductor being arranged in a plane parallel to the plane of the U-shaped conductor connected between said grids.

In combination, an electric discharge dcvice having anelectrode, acircuit connection adapted to betraversed by alternating' currents connected tosaid electr-oda, said circuit connection providing a.passage forvthe circulation oi' iluid, and means for supporting said connection at a voltage nodalpoint for said alternating currents.

16. In combination, an 'electron discharge device having an anode lectrode, a circuit connection comprising a hollow conductor providing a passage for the circulation of fluid and adapte'd to be traversed by high frequency currents connected to said anode, and means for supporting said hollow conductor at a voltagenodal point 17. In combinatioman electron discharge device having an anode'electrode, a pair of hollow conductors each providingV a passage for the circulation of a cooling iluid -connected to said anode electrode, said conductors being traversed by high frequency currents, one of said conductors being an inlet' passage and the other an outlet passage for said uid, and means for supporting each of said conductors at a voltage nodal point thereon for said high frequency currents.

18. A system as defined in claim 15, including a slider in direct contact with said connection for tuning the effective electrical length of said 10 connection..

19. An electron discharge device having a illamentary cathode, a U-shaped connection for feeding heating energy to said cathode, said connection being traversed by high frequency currents employedby said device, and means for supporting said connection at the junction of the legs of said U at a voltage nodal point thereon for said high frequency currents.

20.' Apparatus in accordance with claim 19, including a slider in direct contact with the legs of said U-shaped connection for tuning the effec- -tive elctrical length thereof.

21.'A pair of electron discharge devices each having anode, cathode and grid electrodeaindividual U-shaped connections coupling corresponding electrodes of said devices together, and means for supporting each of said U-shaped connections at a voltage nodal point thereon for the high frequency currents traversing same.

22. A system in accordance with claimfZl,

I characterized in this that said U-shaped connections are tubular conductors, and said means support said conductors at the electrical centers of said U-shaped connections.

423. In combination, a pair of electron discharge devices each having anode, cathode and grid electrodes, individual connections coupling corresponding electrodes of said devices together, the connection between said grids comprising a U- shapedconnection. a circuit including a pair or 'wires connected to the two legs of said U-shaped connection at tapping points,'an adjustable shortcircuiting strap connected across the legs of said U-shaped.connection and located between said tapping points and the trough of said U, the/impedance of said strap and the portion oiflsaidA legs located between said strap and said tapping points being equal to the impedance of-said pair of wires.

24. In combination, a pair of -electron discharge devices each having anode, cathode and grid electrodes,-individual connections coupling corresponding electrodes of said devices together, the connection between said anodes comprising a U-shaped connection, a circuit including a pair of wires connected to the two legs of said U-shaped connection at tapping points, an adjustableshort-circuiting strap connected across the legs of said U-shaped connection and located between said tapping points and the trough of said U, the impedance of said strap and the portion of said egs located between said strap and said tappin points being equal to the impedance of said pair of wires.

25. In' combination, a pair of multi-electrode electron discharge devices, a U-shaped connection coupling one electrode of one of said devices to the corresponding electrode of the other device. a circuit including a pair of wires connected to the two legs -of said U shaped connection at tapping points, an adjustable short-circuiting strap connected across the legs of said U-shapcd connection and located between said tapping points and the trough of said U. the impedance 'f54 of said strap and the portion' of said legs located between said strap and said tapping points being equal to the impedance of said pair of wires:

26. A high frequency system comprising an electron discharge device having a illament, an anode, and a fluid cooled chamber, one or more sources of energy for supplying heating current ,l to said lament and a polarizing potential to ber to enable the cooling iiuid to owtherethrough, and means responsive to failure of said uid to Anow to said chamber for removing the heating current from saidillament and the polarizing potential from said anode.

' 37. A system in accordance with claim 26, characterized in this that said fluid is water, and said means responsive to the failure oi' said water to flow to said chamber includes awater valve in the water supply system, and a relay whose said anode, an inlet and an outlet tor'said chamoperativeness depends upon the position of said valve.

- NILS E. LINDENBLAD. 

